21279056 has 10 divisors (see below), whose sum is σ = 41228202. Its totient is φ = 10639520.

The previous prime is 21279047. The next prime is 21279059. The reversal of 21279056 is 65097212.

It can be written as a sum of positive squares in only one way, i.e., 11669056 + 9610000 = 3416^2 + 3100^2 .

It is a super-2 number, since 2×21279056² = 905596448502272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21279059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664955 + ... + 664986.

Almost surely, 2^21279056 is an apocalyptic number.

It is an amenable number.

21279056 is a deficient number, since it is larger than the sum of its proper divisors (19949146).

21279056 is a wasteful number, since it uses less digits than its factorization.

21279056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329949 (or 1329943 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 21279056 is about 4612.9227177571. The cubic root of 21279056 is about 277.1090987228.

It can be divided in two parts, 21 and 279056, that multiplied together give a triangular number (5860176 = T₃₄₂₃).

The spelling of 21279056 in words is "twenty-one million, two hundred seventy-nine thousand, fifty-six".